118 MR. F. SMITH OK THE GEOGRAPHICAL DISTRIBUTION 



colouring is soon lost when the two forms commingle, which 

 cannot be prevented when they are kept in close proximity. Now 

 the colouring of Vespa rufa is the reverse of this : the more sober- 

 coloured insect is the British ; examples from Nova Scotia are 

 exceedingly bright in colour, much, very much more so than any 

 found in Great Britain ; specimens from Sweden are intermediate 

 in colour. If I am right in considering V. orientalis a variety of 

 V. crahro, then the more highly coloured form is Indian, whereas 

 in Northern China the species again exactly resembles the British 

 in colouring. 



These instances apparently prove that different species are 

 affected by climatal influences in opposite ways : it cannot be 

 laid down as a rule that a species is necessarily of a more sombre 

 colour in colder latitudes. We shall have some further obser- 

 vations to offer on this subject when remarking upon the distribu- 

 tion of the different species of Vespidge. 



In a collection of Hymenoptera made by an entomologist so 

 eminently qualified as Mr. Wallace, the Formicidse (as might be 

 expected) constitute a very important portion, the number of 

 species amounting to about two hundred and eighty. Of these, 

 upwards of two hundred proved new to science. The majority 

 of the larger species were previously known. Formica gigas 

 of India and Malacca was found by Mr. Wallace in Singapore 

 and Borneo. F. compressa, known as Indian, and also from China 

 and the Philippines, is now known to inhabit Borneo ; this Ant, 

 no doubt, will be found throughout the Archipelago, as it has 

 occurred in Australia. It is very interesting to find the Euro- 

 pean genus (as it has hitherto been regarded) Tapinoma occurring 

 in Celebes, Malacca, and Bachian. 



The genus Polyrhachis includes all those species that closely 

 resemble Formica, but which have the thorax and node of the 

 peduncle armed with spines or hooks : of this genus fifty-eight 

 were described, to which number Mr. Wallace has added seventy- 

 seven. As the type of the genus I regard the Formica bihamata 

 of Drury ; it was known as an inhabitant of India and Sumatra ; 

 it has now been captured in Celebes, Bachian, Ceram, and 

 Waigiou. Polyrhachis sexspiiiosa of India and the Philippines 

 has been taken in the Aru Islands, and also in Waigiou. Eight 

 or nine species are known from Africa, six from Australia, and 

 four from Brazil. It would therefore appear that the metro- 

 polis of the genus lies in the East. The species of this genus 

 construct small semicircular nests of a kind of network on the 



